● "Red Flame Battlefield" is adapted from the comic of the same name by WildStorm/DC. The manga has three volumes, published from 2003 to 2004, written bydrawn.
● The English name of the film "RED" is spelled out from the first letter of the word "Retired Extremely Dangerous", which is literally translated as "Retired Extremely Dangerous".
● The average age of the four leading actors in the film, Bruce Willis, Morgan Freeman, Helen Mirren, and John Malkovich is over 63 years old.
● Some scenes of the film were taken from Chinatown in the United States.
● Previously, Morgan Freeman and Bruce Willis had co-starred in "The Night Is In Love"and "Lucky Number Slavin".
● Meryl Streep was originally the intended candidate for the role of Victoria.
● John C. Reilly originally planned to star in the film, but he withdrew from filming halfway through, and his role was replaced by John Malkovich.
● When the film was filmed in Toronto, the police received a call to the police. It was residents of Toronto who heard the sound of machine gun shooting during the filming, and mistakenly thought it was a real gunfight.